Toon Moene wrote :-
> Mark Hahn wrote:
>> > I still see users fling their code at a machine with
> > g77 prog.f && ./a.out
> > and wonder why it's so slow.
>> Well, I could make -O2 -ffast-math -funroll-loops the default (but then,
> I don't think I'll get this past the IEEE754 police @ gcc.gnu.org :-)
However there's nothing to stop Mark (assuming he has control of the
machine) from setting the system up so that the "g77" you get by
default is really a shell script which turns on appropriate
optimisation flags, and also providing a command either to compile
unoptimised, or to change the users $PATH so that they can get to a
"raw" g77.
I know that this is the approach used by Nick McLaren on the big Sun
machines at Cambridge.
http://www.hpcf.cam.ac.uk/prog_franklin_compilers.html
Depending on the interests of your users (are they interested in their
application domain, or in becoming compiler switch experts), they may
prefer a system where someone has already defaulted the compiler to
use an apporpiate set of magic optimisation flags.
-- Jim
James Cownie <jcownie at etnus.com>
Etnus, LLC. +44 117 9071438
http://www.etnus.com
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